I can try! 'Whether' means that there is a choice, and you aren't certain what the answer is. For example: You don't know whether you are using the word correctly or not. You can't decide whether you want to go to the shop. Sometimes you can also use it in place of 'if'. For example: I'll check whether that is true or not. I'll check if that is true or not. Both basically mean the same thing. 'Unless' means 'except if' or 'if not'. For example: Unless you learn good grammar, you will make mistakes. We can play football on Saturday, unless it is raining. I hope that helps!